APA (7th ed.) Citation

Hellwig, G. (1964). Differential operators of mathematical physics: An introduction. Addison-Wesley.

Chicago Style (17th ed.) Citation

Hellwig, Gunther. Differential Operators of Mathematical Physics: An Introduction. Reading, Mass: Addison-Wesley, 1964.

MLA (9th ed.) Citation

Hellwig, Gunther. Differential Operators of Mathematical Physics: An Introduction. Addison-Wesley, 1964.